\documentclass{article}
\usepackage{tikz,amsmath}
\usetikzlibrary{arrows.meta}
\usepackage[graphics,tightpage,active]{preview}
\PreviewEnvironment{tikzpicture}
\begin{document}
\begin{tikzpicture}[>=Stealth]
    \draw [semithick] (-1.5, 0) node [anchor=east] {$A$} -- (1.5, 0) node [anchor=west] {$B$};
    \fill (0, 1.5) circle[radius=2pt] coordinate[label=90:$M$] (M);
    \draw [semithick] (M) -- (0, 0) node [anchor=north] {$O$};
    \draw  (0, 0.3) -- (0.3, 0.3) -- (0.3, 0);
\end{tikzpicture}
\end{document}
